Abstract: The disclosure provides a syringe for hypodermic injections having a needle and including a barrel defining a chamber in fluid communication with the needle, a guide member disposed within the chamber, a plunger disposed within the chamber and between the guide member and the needle, the plunger having a stem extending through the guide member, and first means for allowing movement of the guide member relative to the barrel in one direction and for preventing return movement of the guide member and second means for allowing movement of the plunger relative to the guide member and for preventing return movement of the plunger, the second means including lost motion means to permit limited return movement of the plunger so that the user can determine that injection into a vein has been achieved.